CDC Monitors Shortage of Hib Vaccine

Nov. 21 -- THURSDAY, Nov. 20 (HealthDay News) -- U.S. health officials said Thursday that a shortage of vaccine is leading them to monitor Hib infections, one of the most important causes of bacterial illness in young children.

Though the agency has yet to see an increase in cases, the stepped-up surveillance was prompted by a disruption in the supply of vaccine that has virtually eliminated Hib (Haemophilus influenzae type b) infections since it was introduced in 1988.

Hib infection can cause a variety of illnesses, including meningitis (inflammation of the membranes covering the spinal column and brain), blood stream infections, and pneumonia, according to the U.S. Centers for Disease Control and Prevention. Hib is not a cause of the seasonal flu.

"The shortage is not serious but it is concerning," said Michael Jackson, an epidemiologist with the CDC.

The shortfall was caused by a recall of certain lots of Hib conjugate vaccine, and then the suspension of production by drug maker Merck & Co. last December. Merck originally expected to resume production late this year, but delays have pushed that timetable back to the middle of 2009, the CDC said in its Nov. 21 Morbidity and Mortality Weekly Report.

One reason the vaccine shortage hasn't been more serious is that drug maker Sanofi-Aventis also makes Hib vaccine, Jackson said.

Before the introduction of the vaccine, some 20,000 U.S. children would get serious and sometime fatal Hib infections each year, the CDC noted.

Merck spokeswoman Amy Rose said that problems with the vaccine's sterilization process necessitated recalling the vaccine and then stopping production. The vaccines are marketed as PedvaxHIB and Comvax.

To manage the shortage, health officials are recommending giving the Hib vaccine to infants, but holding off on a recommended booster shot for children age 12 to 15 months, except those at increased risk for Hib disease.

"Right now the recommendations are to make sure all children get the primary vaccine series, and providers should defer giving the booster dose until the vaccine supply increases," Jackson said. "We are not worried about sudden increases in Hib disease, but we are worried over time that, not having the booster, we could start to see increases in Hib," he said.